Apparatus for impregnating horizontally transported corrugated paperboard

ABSTRACT

This invention relates to simplified apparatus for impregnating horizontally advancing corrugated paperboard containing a succession of transversely extending flutes. The apparatus includes a lower housing and an adjustable closure member defining a sealed chamber placed in communication with the paperboard flutes by flute sealing means including upper and lower sealing members engaged, respectively, with the upper and lower surfaces of the advancing paperboard. To adjust the pressure with which the sealing members contact the paperboard and to adjust the spacing between the sealing members, the upper and lower sealing members are connected directly with the closure member and housing, respectively, and the housing and closure members are adjustably spaced by a pair of adjustable spring devices connected therebetween. In accordance with a more specific feature of the subject invention, the sealing members each include a paperboard engaging surface which is curved when not in use but which becomes planar in configuration when in contact with an advancing paperboard surface due to the heating effect thereof.

United States Patent 11 1 Lau et al.

1 1 Jan.7, 1975 APPARATUS FOR IMPREGNATING HORIZONTALLY TRANSPORTED CORRUGATED PAPERBOARD [76] Inventors: Giinther Lau, Glogauer Str. 22,

8541 Katzwang; Edmund Bradatsch, Huttenwerkstr. 5, 8481 Weiherhammer; Hermann-J. Brand], Virchowstr. 33, 85 Nuremberg, all of Germany 22] Filed: Jan. 8, 1973 21 Appl. No.: 321,788

[30] Foreign Application Priority Data Jan. 14, 1972 Germany 2201740 [52] US. Cl. 118/50, 118/317 [51] Int. Cl B05b 13/06 [58] Field of Search 118/50, 50.1, 317, DIG. 3, 118/48-495; 117/95, 119, 96

[56] References Cited UNITED STATES PATENTS 3,669,064 6/1972 Hoelzinger et al 118/50 X 3,669,067 6/1972 Achermann et al. 118/50 3,695,219 10/1972 Arian et al 118/50 Primary Examiner-Morris Kaplan Attorney, Agent, or Firm-Silverman & Cass, Ltd.

[57] ABSTRACT This invention relates to simplified apparatus for impregnating horizontally advancing corrugated paperboard containing a succession of transversely extending flutes. The apparatus includes a lower housing and an adjustable closure member defining a sealed chamber placed in communication with the paperboard flutes by flute sealing means including upper and lower sealing members engaged, respectively, with the upper and lower surfaces of the advancing paperboard. To adjust the pressure with which the sealing members contact the paperboard and to adjust the spacing between the sealing members, the upper and lower sealing members are connected directly with the closure member and housing, respectively, andthe housing and closure members are adjustably spaced by a pair of adjustable spring devices connected therebetween. In accordance with a more specific feature of the subject invention, the sealing members each include a paperboard engaging surface which is curved when not in use but which becomes planar in configuration when in contact with an advancing paperboard surface due to the heating effect thereof.

10 Claims, 5 Drawing Figures Patented Jan. 7, 1975 3,858,550

3 Sheets-Sheet 1 Fig.1

Patented Jan. 7, 1975 3,858,550

3 Sheets-Sheet 2 Patented Jan. 7, 1975 3 Sheets-Sheet 5 APPARATUS FOR IMPREGNATING HORIZONTALLY TRANSPORTED CORRUGATED Y PAPERBOARD BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to apparatus for impregnating a horizontally transported corrugated paperboard with an impregnate supplying unit positioned adjacent one longitudinal edge of the corrugated paperboard and a suction unit adjacent the other longitudinal edge. Both the supplying unit and the suction unit include sealing means adjustable in terms of height for forming a seal with the longitudinal edges of the corrugated paperboard.

2. Description of the Prior Art In known devices of this type such as disclosed in U.S. Pat. No. 3,669,064, issued June 13, 1972, to Hoelzinger et a1 and assigned to the assignee of this invention, the supplying unit and the suction unit include a supplying box and a suction box, respectively, sealed in communication with associated longitudinal edges of the advancing paperboard by means of a rigid member having a plastic coating and connected with the respective box. On the upper side of each longitudinal edge of the corrugated paperboard, a bar-like sealing strip is directly pressed by an adjustable pressure spring. This strip is provided, likewise, with a plastic coating along its underside. The edge of the sealing strip remote from the corrugated paperboard is held in sealing fashion against the respective supplying or suction box.

This known type of sealing apparatus employing one fixed and one movable sealing strip, of course, automatically adjusts to the thickness and possibly also to the changes in the thickness of the corrugated paperboard but the known apparatus requires a seal against the guidance surface on the supplying or suction box in addition to the seal against the corrugated paper strip. Furthermore, the sealing strip includes a flat surface for engaging the paperboard. It is possible only in a very expensive manner to place the sealing strip in a sealing action against the corrugated paperboard at all points along the corrugated paperboard. An attempt has been made to resolve this difficulty by means of an additional plastic coating, but the plastic coating is subject to very severe wear. In the known arrangement, it is a further disadvantage that the supplying and suction boxes are so made that the structural parts, contained in them, can be serviced and maintained only with great difficulties. 1

In another known device for impregnating a corrugated paperboard such as disclosed in U.S. Pat. No. 3,669,067, issued June 13, 1967, to Ackermann et al and assigned to the assigneee of the present invention, the sealing effect against the longitudinal edges of the corrugated paper strip is achieved by means of elastic lips or sealing flanges. These sealings flanges are formed of expensive materials because only expensive materials can sustain the wear and tear to which the lips are subjected. It is a further disadvantage of this second type of apparatus that the press-on force of the elastic lip seals is predetermined and cannot be adjustably altered.

SUMMARY OF THE INVENTION The primary object of this invention is to provide an apparatus for impregnating corrugated paperboard including sealing means for sealing the longitudinal edges of the corrugated paperboard wherein the sealing means are improved in terms of operation and simpli fied in terms of design. A further object of this invention is to provide sealing means for a paperboard impregnating apparatus including both supplying and suction boxes (each having an open lower housing and a closure member) adapted to facilitate easy access to the interior thereof so that the structural parts located therein can be checked and serviced.

The invention solves the problems discussed above in the following manner: an upper sealing member in the form of an L-shaped bracket is connected with the closure member of each box, a lower sealing member is, likewise, connected with the lower housing of each box of the apparatus in the form of a second L-shaped bracket, the closure member is flexibly connected with the housing, and the closure member rests on an adjustable spring which works against the weight of the closure member.

This arrangement offers the advantage that the supplying and suction boxes are each divided into two parts and that the upper part is made in the form of a removable closure member. As a result of this, the structural parts arranged within the box can be easily and simply serviced after the closure member has been taken off.

On the removable closure member of each box, an upper sealing member is arranged for engagement with the upper surface of the corrugated paperboard wherein the sealing member forms part of the removable closure member. The upper sealing member is so made that it can be removed simultaneously with the closure member. Nevertheless, the disclosed design offers the advantage that, when the closure member is put in place, the upper sealing member, as in the known apparatus, will be adjusted automatically to the thickness of the particular corrugated paperboard being impregnated. To provide press-on force for the upper sealing member, the entire weight of the upper seal member is employed. In order to adjust the press-on force to the particular desired value, the weight of the closure member is counteracted by a pair of spring devices extending between the lower housing and closure member.

In order to facilitate the simple attachment of the upper sealing member to the closure member of the supplying and suction units, the sealing members for each unit, according to another feature of the invention, are L-shaped brackets which are flexibly connected in such a manner that, when not in operation, the L-shaped brackets are arched in the middle away from the paperboard while under residual stress, and bend into a straight position during operation due to the heating of the leg portion of the brackets in contact with the paperboard. The residual or prestressing of the vided with several spaced slots defining a plurality of bracket sections.

In order to be able to exert a defined prestressing force upon each section of the L-shaped bracket, each L-shaped bracket section, according to a further feature of the invention, is clamped under adjustable pressure supplied by a plurality of springs mounted on associated fasteners such as screws extending through longitudinal apertures in the sections, respectively.

To keep the wear and tear as well as the friction on the sealing members as small as possible, each L- shaped bracket, according to another feature of the invention, is supplied with a metal wearing plate. Of course, wear resistant material is chosen for this purpose.

According to another object of the invention, the removable closure member is sealed against the lower housing of the impregnating apparatus. For this purpose, an elastic sealing hose is arranged between the side and rear edges of the closure member and the lower housing.

In order to be able to line up the closure member with the lower housing, a mounting means is provided, according to a further feature of the invention, between the closure member and the lower housing. The mounting means includes a pair of eccentric pins along the backside of the impregnation apparatus box; these eccentric pins are rotatably mounted in the lower housing and engage longitudinal slots in the closure member. The eccentric pins preferably have support sleeves for supporting the closure member. In order to facilitate alignment of the closure member parallel to the direction of movement of the corrugated paperboard, a pair of eccentric pins are also arranged along the sides of the impregnating apparatus box.

To avoid the necessity of removing the entire closure member to service the structural parts located in the impregnating apparatus unit adjoining the longitudinal edges of the paperboard, the closure member includes maintenance openings according to another feature of the invention.

The invention is-described ingreater detail below with the help of an example illustrated in the drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic cross-sectional view of the impregnating apparatus according to this invention taken laterally to the direction of movement of the corrugated paperboard;

FIG. 2 is a cross-sectional view taken along line 2--2 of the apparatus illustrated in FIG. 1;

FIG. 3 is a view of the upper sealing member upper surface of the corrugated paperboard;

FIG. 4 is a cross-sectional view taken along line 4--4 of the apparatus illustrated in FIG. 3; and

FIG. 5 is a cross-sectional view taken along line 55 of the apparatus illustrated in FIG. 3.

For reasons of simplicity, only the impregnate supplying unit of the apparatus for impregnating a corrugated paperboard in accordance with this invention will be described. The suction unit of the apparatus located on the opposite side of the paperboard from the impregnate supplying unit is made in the same manner in terms of design as is the impregnate supplying unit. [It is noted that each unit serves a different function dependent upon the type of apparatus located within the chamber defined by each box. For example, the supplyfor the ing unit could include spray nozzles (not illustrated) for injecting impregnate into the paperboard flutes and the suction unit could include screens for receiving the discharge from the paperboard flutes] The impregnate supplying unit 1 for the injection of impregnate, such as wax, into the corrugated paperboard 2 includes a supplying box 3 which is movable supported on the upper portion of a frame 4 of the impregnate supplying unit 1. Supplying box 3 moves laterally to the direction of movement of the corrugated paperboard 2 in the direction of arrow I and may be fixed in any desired position. The supplying, box 3 includes a lower or receiving housing 5 containing an opening and a closure member or delivery housing (for covering the receiving housing opening). The housings form respective upper and lower chambers in communication with each other. Closure member 6 can be lifted off the lower housing 5 and can be swung around an axis parallel to the rear wall of the supplying box 3'to a limited extent. (Housing 5 includes first and second portions surrounding the housing opening, wherein the first portion located on side 7 is adjacent the longitudinal edge of the paperboard and the second portion on side 20 is remote from the longitudinal edge of the paperboard).

On side 7 of the box facing toward the corrugated paperboard 2 there is attached,'on the lower housing 5 and on closure member 6, a pair of sealing flange members including L-shaped brackets 8, 9. Because the seal forming L-shaped bracket 8 adjacent the upper surface of corrugated paperboard 2 and the seal forming L- shaped bracket 9 adjacent the lower surface of the corrugated paperboard are identically fashioned, only bracket 8 will be described.

As can be seen in FIG. 3, the L-shaped bracket 8 is attached'at its ends l0, 11 by means of screws 12, in such a manner that each end of the L-shaped bracket can move around screw 12. Furthermore, L-shaped bracket 8 has a plurality of longitudinal apertures 13 spaced at intervals from each other. Through these apertures, fasteners, such as screws 14, are screwed into closure member 6. Spring plates 15 mounted on the screws press on the attachment leg 16 of the L-shaped bracket 8. As a result of this, the attachment leg 16 is pressed against closure member 6 with a predetermined force.

Attachment leg 16 also contains a plurality of longitudinally spaced, open ended vertical slots 17 provided between longitudinal apertures 13. Accordingly, the attachment leg of each bracket is divided into sections which are individually pressed against the associated closure member or housing by separate spring plates 15.

As can be seen in FIG. 3, the L-shaped bracket is curved upward when the impregnate supply unit is out of operation. During operation, the sealing leg 18 heats up considerably more than the attachment leg 16, as a result of which the L-sh'aped bracket is bent straight and rests over its entire length on the upper surface of corrugated paperboard 2 in a sealing manner therewith. When cold and when not in operation, the L- shaped bracket 8 resumes its initial position illustrated in FIG. 3. If the L-shaped bracket 8 were not precurved to the extent described, the bracket would become curved or arched, during operation, due to the differing heating effects, as a result of which good sealing with the corrugated paperboard could be impaired.

The L-shaped bracket is provided with a metal wearing plate 19 which extends over the entire undersurface of the sealing leg 18 of the L-shaped bracket 8. In order to facilitate the insertion of a longitudinal edge of the corrugated paperboard 2, the metal wearing plate 19 is U-shaped in cross-section and extends upwardly toward the corrugated paperboard. Plate 19 curves back for attachment toward the attachment leg 16 and is preferably screwed onto the top side of the attachment leg 16.

To make sure that the upper sealing member, constituted by the L-shaped bracket 8, will automatically come to rest against the top side of the corrugated paperboard in a sealing manner, closure member 6 can be moved with respect to the lower housing 5. To make sure that closure member 6 can be swung to a limited extent around a parallel axis with respect to the direction of movement of the corrugated paperboard, mounting means including flexible bearings 21 are arranged in the corners of the backside of the lower housing 5. See FIG. 2. A corner plate 22 in each case has a borehold 23 within which an eccentric pin 24 is rotatably mounted. The eccentric pins 24 include support sleeves 25 disposed therearound. Closure member 6 also includes weldable 'cornerplates 22 containing longitudinal holes 26 which extend parallel to the direction of movement of the corrugated paperboard 2. The eccentric pins 24 engage, with leeway, in the longitudinal holes 26, respectively, so that closure member 6 can be moved to a limited extent with respect to the lower housing 5.

By turning the eccentric pins 24 it is possible to adjust the closure member 6 with respect to lower housing 5, more specifically, in the direction toward or away from the corrugated paperboard.

In order to be able to adjust closure member 6 with respect to lower housing 5 parallel to the direction of movement of the corrugated paperboard 2, additional eccentric pins are arranged along the sidewalls 35 of the supplying box 3, (see FIG. 2) but the longitudinal holes 26' now extend perpendicularly to the direction of movement of the corrugated paperboard. Here, the supporting sleeves can be omitted from the eccentric pins.

The edges of closure member 6 and of the housing 5, which face each other, are sealed by means of an elastic sealing hose 27. It is preferably attached to the edges of the housing 5, for example, by glueing.

In order to be able to adjust the spacing between the sealing member 8, 9 to accomodate various thicknesses of the corrugated paperboard, there are a pair of spring adjustment devices 28 positioned in the corners at each end of the front side 7 of the supplying box 3. For this purpose, a pair of plates 29 are welded onto the lower housing 5. Above each plate 29, on closure member 6, a plate 30 is welded which is provided with a thread hole into which an adjusting pin 31 can be screwed. The underside of this adjusting pin 31 rests on plate 29. Between plate 30 and the lower end of the adjusting pin 31, a pressure spring 32 is inserted. By turning the adjustment pin 31, the space between sealing members can be adjusted depending upon the thickness of corrugated paperboard to be processed. The press-on force of the sealing members against the corrugated paperboard 2 may also be adjusted to a limited degree.

In the areas facing toward the corrugated paperboard 2, inside supplying box 3, a number of nozzles (not illustrated) are arranged to inject the impregnating agent into the open longitudinal edge of the corrugated paperboard 2. These nozzles must be serviced. In order not to have to remove the closure member constantly,

a service opening 33 is provided in closure member 6 over these nozzles. The service opening is closed off by a removable cover 34. Identical service openings can be arranged in the suction unit which contains screens.

What is claimed is:

1. Apparatus for impregnating horizontally advanc-- ing paperboard containing a succession of transversely extending flutes. wherein said paperboard advances between opposed housings communicating with said flutes and adapted to pass impregnant through said flutes from a delivery housing to the opposed receiver housing, each housing comprising a. respective upper and lower freely communicating chambers;

b. means adjustably biasing said chambers to a generally sealing relationship at the open peripheries thereof;

c. said chambers including an elongated, opening to effect said communication with said flutes, flute sealing means for sealing the flute ends from the atmosphere and for providing a communication path for impregnate moving between the housings and the paperboard flutes, said flute sealing means including 1. a moveable, heat conductive lower flange member connected with said lower chamber for sealing engagement with the lower surface of the paperboard,

2. a moveable, heat conductive upper flange member connected for movement with said upper chamber for sealing engagement with the upper surface of the paperboard,

3. said flange members being each normally of a predetermined arcuate configuration and spaced furthest from said paperboard a predetermined distance at the mid-point of the flange member, and

4. whereby upon said moveable flange members being heated by the impregnant passing therethrough, and due to the effect of said heating, assume a planar configuration and sealing relationship with said paperboard, and I d. adjusting means connected with said chambers for adjusting the pressing force with which said chambers contact the upper and lower surfaces, respectively, of the paperboard by adjusting the spacing between said chambers.

2. Apparatus as defined in claim 1, wherein each said flange includes an L-shaped bracket having a plurality of vertically extending spaced slots in a vertical leg thereof through which relatively movable connection is made with a respective chamber and said flute sealing means is effected at the horizontal leg of said bracket.

3. Apparatus as defined in claim 2, wherein said flute sealing means further includes means for adjustably prestressing each said L-shaped bracket intermediate its ends, said prestressing means including a plurality of fasteners and corresponding spring elements connected with said closure member and said housing through intermediate ones of said slots, respectively. for applying adjustable spring pressure to said L-shaped bracket.

4. Apparatus as defined in claim 2, wherein said seal is formed by a metal wearing plate connected with said horizontal leg.

5. Apparatus as defined in claim 1, wherein said means to effect a generally sealing relationship of the chambers includes an elastic sealing hose disposed between said peripheries.

6. Apparatus as defined in claim 1, and further including mounting means for adjustably positioning said upper chamber with respect to said lower chamber, said mounting means including a first pair of eccentric pins rotatably mounted in said lower chamber and received, respectively, within a first pair of longitudinal slots contained in said upper chamber.

7. Apparatus as defined in claim 6, wherein said mounting means further includes a pair of support sleeves associated with said eccentric pins, respectively, for supporting said upper chamber.

8. Apparatus as defined in claim 6, wherein said mounting means further includes a second pair of eccentric pins rotatably mounted within said lower chamber and received. respectively, in a second pair of Iongitudinal slots contained in'said upper chamber, said 1 second pair of longitudinal slots being perpendicular to said first pair of longitudinal slots.

9. Apparatus as defined in claim 1, wherein said upper chamber contains a service opening of sufficient size to provide access to the interior of the lower chamber for maintenance and adjustment of apparatus located therein and wherein said upper chamber includes a removable cover sealingly closing the service open- 10. Apparatus as defined in claim 1, wherein said upper chamber and upper flange members are gravity biased toward the paperboard, and further wherein said adjusting means includes an adjustable tension spring for opposing the weight of said upper chamber and upper flange members to the extent necessary to apply a predetermined force through said upper flange member to the paperboard. 

1. Apparatus for impregnating horizontally advancing paperboard containing a succession of transversely extending flutes, wherein said paperboard advances between opposed housings communicating with said flutes and adapted to pass impregnant through said flutes from a delivery housing to the opposed receiver housing, each housing comprising a. respective upper and lower freely communicating chambers; b. means adjustably biasing said chambers to a generally sealing relationship at the open peripheries thereof; c. said chambers including an elongated opening to effect said communication with said flutes, flute sealing means for sealing the flute ends from the atmosphere and for providing a communication path for impregnate moving between the housings and the paperboard flutes, said flute sealing means including
 1. a moveable, heat conductive lower flange member connected with said lower chamber for sEaling engagement with the lower surface of the paperboard,
 2. a moveable, heat conductive upper flange member connected for movement with said upper chamber for sealing engagement with the upper surface of the paperboard,
 3. said flange members being each normally of a predetermined arcuate configuration and spaced furthest from said paperboard a predetermined distance at the mid-point of the flange member, and
 4. whereby upon said moveable flange members being heated by the impregnant passing therethrough, and due to the effect of said heating, assume a planar configuration and sealing relationship with said paperboard, and d. adjusting means connected with said chambers for adjusting the pressing force with which said chambers contact the upper and lower surfaces, respectively, of the paperboard by adjusting the spacing between said chambers.
 2. Apparatus as defined in claim 1, wherein each said flange includes an L-shaped bracket having a plurality of vertically extending spaced slots in a vertical leg thereof through which relatively movable connection is made with a respective chamber and said flute sealing means is effected at the horizontal leg of said bracket.
 2. a moveable, heat conductive upper flange member connected for movement with said upper chamber for sealing engagement with the upper surface of the paperboard,
 3. said flange members being each normally of a predetermined arcuate configuration and spaced furthest from said paperboard a predetermined distance at the mid-point of the flange member, and
 3. Apparatus as defined in claim 2, wherein said flute sealing means further includes means for adjustably prestressing each said L-shaped bracket intermediate its ends, said prestressing means including a plurality of fasteners and corresponding spring elements connected with said closure member and said housing through intermediate ones of said slots, respectively, for applying adjustable spring pressure to said L-shaped bracket.
 4. Apparatus as defined in claim 2, wherein said seal is formed by a metal wearing plate connected with said horizontal leg.
 4. whereby upon said moveable flange members being heated by the impregnant passing therethrough, and due to the effect of said heating, assume a planar configuration and sealing relationship with said paperboard, and d. adjusting means connected with said chambers for adjusting the pressing force with which said chambers contact the upper and lower surfaces, respectively, of the paperboard by adjusting the spacing between said chambers.
 5. Apparatus as defined in claim 1, wherein said means to effect a generally sealing relationship of the chambers includes an elastic sealing hose disposed between said peripheries.
 6. Apparatus as defined in claim 1, and further including mounting means for adjustably positioning said upper chamber with respect to said lower chamber, said mounting means including a first pair of eccentric pins rotatably mounted in said lower chamber and received, respectively, within a first pair of longitudinal slots contained in said upper chamber.
 7. Apparatus as defined in claim 6, wherein said mounting means further includes a pair of support sleeves associated with said eccentric pins, respectively, for supporting said upper chamber.
 8. Apparatus as defined in claim 6, wherein said mounting means further includes a second pair of eccentric pins rotatably mounted within said lower chamber and received, respectively, in a second pair of longitudinal slots contained in said upper chamber, said second pair of longitudinal slots being perpendicular to said first pair of longitudinal slots.
 9. Apparatus as defined in claim 1, wherein said upper chamber contains a service opening of sufficient size to provide access to the interior of the lower chamber for maintenance and adjustment of apparatus located therein and wherein said upper chamber includes a removable cover sealingly closing the service opening.
 10. Apparatus as defined in claim 1, wherein said upper chamber and upper flange members are gravity biased toward the paperboard, and further wherein said adjusting means includes an adjustable tension spring for opposing the weight of said upper chamber and upper flange members to the extent necessary to apply a predetermined force through said upper flange member to the paperboard. 